Nesting For Loops Error

Tell us what’s happening:
“TypeError: unknown: Cannot read property ‘0’ of undefined”

How can I fix this? x.x

Your code so far

function multiplyAll(arr) {
  var product = 1;
  // Only change code below this line
  for (var a = 0; a < arr.length; a++);{
    for (var b = 0; b < arr[a].length; b++){
      product = product * arr[a][b];
  // Only change code above this line
  return product;

// Modify values below to test your code

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36.

Link to the challenge:

Not sure if you realize you have a semi-colon between the closing ) and the opening { of your outer for loop statement. It is causing your code to not behave the way you are expecting.